Manufacturers of cosmetic products are not only interested in continually improving the properties of their products and in meeting growing consumer demands, they are also—conversely—seeking to keep the number of raw materials used as small as possible in order to arrest increasing raw material costs by eliminating complexity. For this reason, there is a particular demand for raw materials which not only have improved properties, but also show additional effects such as, for example, stabilization (for example in the case of active substances) or the replacement of other formulation ingredients (for example preservatives).
In recent years, cationic surfactants of the esterquat type have grown into important cosmetic raw materials because they not only have good dermatological compatibility, they also condition the skin and the hair, i.e. provide them with pleasant sensory properties, more especially a particular softness. The esterquats used for this purpose are quaternized esters of alkanolamines with long-chain fatty acids (C12-20 range) which, unfortunately, sometimes show two disadvantages in the end formulations, i.e. separation of the emulsions or gelation are observed in the event of prolonged storage, particularly under temperature stress, which are both undesirable to the consumer.
Accordingly, the complex problem addressed by the present invention was to find a way of enabling relatively long-chain esterquats to be more easily and stably incorporated in cosmetic preparations while, at the same time, saving preservative and also improving the stability of special active ingredients, such as UV filters for example.